Fix ImportLens plugin to work with GHC 8.10

[Ailrun]

Fixes #355.

[Ailrun]

@mouse07410 Now it's fixed.

[mouse07410]

Sorry, it still fails to compile:

[14 of 20] Compiling Ide.Plugin.ImportLens ( src/Ide/Plugin/ImportLens.hs, dist/build/Ide/Plugin/ImportLens.o, dist/build/Ide/Plugin/ImportLens.dyn_o )

src/Ide/Plugin/ImportLens.hs:181:47: error:
    Not in scope: data constructor ‘GHC.NotQualified’
    No module named ‘GHC’ is imported.
    |
181 | isQualifiedImport ImportDecl{ideclQualified = GHC.NotQualified} = False
    |                                               ^^^^^^^^^^^^^^^^

src/Ide/Plugin/ImportLens.hs:182:47: error:
    Not in scope: data constructor ‘GHC.NotQualified’
    No module named ‘GHC’ is imported.
    |
182 | isQualifiedImport ImportDecl{ideclQualified = GHC.NotQualified} = True
    |                                               ^^^^^^^^^^^^^^^^
cabal: Failed to build haskell-language-server-0.3.0.0 (which is required by
exe:haskell-language-server from haskell-language-server-0.3.0.0 and
exe:haskell-language-server-wrapper from haskell-language-server-0.3.0.0). See
the build log above for details.

[mouse07410]

It looks like this PR is missing this:

diff --git a/src/Ide/Plugin/ImportLens.hs b/src/Ide/Plugin/ImportLens.hs
index 48110bc..86d38fe 100644
--- a/src/Ide/Plugin/ImportLens.hs
+++ b/src/Ide/Plugin/ImportLens.hs
@@ -31,6 +31,7 @@ import           Development.IDE.Core.Shake     (use, IdeState (..))
 import           Development.IDE.GHC.Compat
 import           Development.IDE.GHC.Error      (realSpan, realSrcSpanToRange)
 import           Development.IDE.GHC.Util       (HscEnvEq, hscEnv, prettyPrint)
+import           GHC
 import           GHC.Generics                   (Generic)
 import           Ide.Plugin
 import           Ide.Types

That patch seems to fix it.

[Ailrun]

@mouse07410 Thanks, I will fix that and merge after CI succeed.

[pepeiborra]

Sorry for all the pain, I merged a previous PR that broke this